I downloaded this ages ago but subsequently lost it in a crash. Recently I've found it again to download but its incomplete. I can't remember whether my original was complete or not! Was it always available in complete form?

I guess you are referring to the infamous second take of Polar Bear. It was supossedly recorded on November of 1970, at a location unknown to me. If the date is right, it certainly features Barry Mitchell on bass. Maybe John can throw some light on this.